"From the very start, from the first steps, we supported and continue to support your efforts aimed at restoring civil peace," Putin told Mr. Annan, according to Russian news agencies. "We will do everything that depends on us to support your efforts," he added.

But the Kremlin leader offered no indication that Russia will support a UN Security Council resolution to be put forward Wednesday. The proposed resolution, backed by the US, Britain, and France, would extend the UN observer mission by 45 days – the mandate is otherwise set to expire on Friday – but would put future implementation of the Annan plan under Chapter 7 of the UN Charter, which might open the door to the legal use of outside force.

On Monday, Russian Foreign Minister Sergei Lavrov accused the West of employing "blackmail," by threatening to block any renewal of the UN observers' mandate unless Russia backed a Chapter 7 resolution on Wednesday.

Last year then-Russian President Dmitry Medvedev ordered Russia's UN envoys to abstain on Resolution 1973, which authorized the use of force to protect civilians in Libya but developed into a rebel drive for regime change backed by NATO airpower. Russia has vowed not to allow any similar resolution about Syria to pass the Security Council.

"Medvedev isn't president anymore, there's another person at the top in Russia now, and that's Putin," says Mr. Yevseyev. "It's senseless to try to pressure Putin; in fact it might lead to the opposite result."

Coming to a compromise?

Foreign Minister Lavrov said Tuesday that Russia might reach a compromise with the West similar to the one that was forged at a meeting of leading powers in Geneva last month. But that deal only saw the light of day after all language calling for Assad's removal or any sort of outside intervention in the conflict was removed from the draft resolution on Russia's demand.

In an otherwise anodyne statement about his "very good" meeting with Putin Tuesday, Mr. Annan hinted at the same outcome. "I would hope that the [Security] Council will continue its discussions and hopefully find language that will pull everybody together for us to move forward on this critical issue," he said.

"In effect, this tells us that all avenues for diplomacy have already been pretty much exhausted," says Sergei Strokan, a foreign policy columnist with the Moscow business daily Kommersant.

"It's all about 'red lines' now. For the West, it's any role for Assad in any future Syrian government. For Russia, the red line is any kind of outside intervention, especially based on a Chapter 7 resolution.... Everybody's talking about peace and political solutions, but in fact diplomacy is totally deadlocked," he says.

"Why should Russia be so stubborn, right up to the bitter end? You have to understand that for Moscow this isn't just about Syria. It's about the mechanism for solving such situations. Putin wants to prevent any precedent that might authorize the use of outside force to engineer change in a crumbling authoritarian regime, wherever it may be," Mr. Strokan adds.

"Maybe next time it might be Belarus or, who knows, one day even Russia?"